<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        .box{
            background-color: #ff9c9c;
            /* overflow: hidden; */
        }
        .box>div{
            
            float: left;
        }
        .d1{
            width: 300px;
            height: 300px;
            background-color: #d4ff83;
        }
        .d2{
            width: 200px;
            height: 200px;
            background-color: #83ffff;
        }
        .d3{
            width: 200px;
            height: 200px;
            background-color: #ec83ff;
        }

        .box::after{
            content: "";
            display: block;
            clear: both;
        }
    </style>
</head>
<body>
    <div class="box">
        <div class="d1"></div>
        <div class="d2"></div>
        <div class="d3"></div>
    </div>
</body>
</html>